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Old 02-08-2015, 02:24 AM   #56 (permalink)
BabyDiesel
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Big Blazin' - '88 Chevrolet K5 Blazer Silverado
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The big problem with these engines is the blocks breaking. Pull the pan off the 6.2 (before you buy it) and inspect for cracks on the block where the main caps bolt too. You will usually see a crack running from the bottom, all the way up.

If you have no visible cracks, the block is in good condition and the rest is a lot simpler to deal with LOL.

I would factor in rebuilt/balanced injectors into your parts cost as well. A weak injector will cause a bunch of small issues, but left to get worse and they could put a hole in the pistons.

I'd look into a good electric lift pump as well. You want it to have a good amount of flow (35GPH minimum) and you 5psi to be your minimum pressure. The electronic 6.5TD's can use 9-14psi but our mechanical pumps don't need that much.

If you are not happy with your performance, try replacing the IP with a rebuilt unit, calibrated to your specific needs. An old IP may start, idle and drive normally, but if it's weak it won't have any power. So don't think just because you heard these things are slow, means that it HAS to be that way LOL. I got a big performance increase with my 6.5TD mechanical pump and it sounds even angrier and rips at the ground now...even with 3.42's.

The swap won't be all that hard, in terms of an engine swap. You just need to run new fuel lines, new wiring and some other stuff. A lot of the wiring could be adapted or taken from a parts truck of the engine (if he didn't strip the harness off of it).

Most of the 6.2/6.5 diesels have just a fuel float/sender in the tank and an external fuel pump. You could, hypothetically, use an in tank pump, but that seems impractical and needlessly expensive.

These external style of fuel pumps can be found just about anywhere, it doesn't even have to be specifically for diesel either. I used a low pressure carb pump on my 6.2 for a few months and it held together fine, even though I run 1L of TC-W3 oil through each tank (these old diesels like the extra lubrication)

My Carter P4070 is a sub-$100 pump that is proven to be one of the strongest, longest lasting in the low pressure fuel pump market. I highly recommend it but I've only wired it up and tested it out. I've yet to drive the truck, It's currently got no interior or drivetrain.

What injectors would you personally suggest? I see conflicting ideas about inj. online.
Go for Genuine Bosch injector nozzles. The body of injector is only for fitment purposes only. I would go with 6.5L short body injectors, just because it will allow you to, potentially, turbo the truck later without fitment issues on the turbo manifold. The stock, long body 6.2L injector lines can be wrestled to fit onto the injectors with no problems at all. You just have to hold the end into the injector very hard and then tighten the nut.

So just go with Bosch nozzled, 6.5TD injectors. Buy em from this guy and you don't have to worry about much more:

http://www.ebay.com/itm/CHEVY-GMC-6-...item25648e3b05

I also hear good things about these guys IP's as well. A nice rebuilt 6.2 pump, at stock fuel levels, should provide more power without much of a mileage hit. You can buy em both for $450 without shipping, which is a helluva deal, if you ask me


I don't have any videos and the truck is currently not-running. I spent soooo much time getting my 6.5TD pump rebuilt and fine-tuned (by myself) and once I got the power, the 700R4 died LOL

I always thought I had 2.25" exhaust but I can see that it was cut out to make 2.5" at some point. I definitely want to get an H-pipe for mine too and a set of Flowmaster 40's. I usually don't like Flowmasters, but they sound amazing on the diesels.

Most conventional oils are not meant to be burnt and have additives that can complicate things, but that's mostly a concern for newer diesels. I would suggest using a 2-stroke oil (TC-W3 is a low smoke formula) or SAE 30 oil, not 5w30, just SAE 30. I couldn't find much around here, but had luck finding them in some heavy equipment places. I found some at a local Cat dealership, I haven't used it before but I want to compare it to the the 2-stroke stuff.

82 was the first year they were produced and also the one year they had coarse thread injectors...which limits your injector choices to just long body/coarse thread. There are no short body injectors made for that year, that I know of, so you will run into fitment issues when going with turbo. That is the only difference, otherwise everything is pretty much the same.

More year info, 82-84 had a dual spin-on fuel filter system. One large filter/water separator on the firewall and a smaller filter on the back of the intake. I have this system, but have since modified a 6.5TD fuel filter manager to replace the manifold mounted filter. This should give me about the best OEM filtering setup.

85-92 had one manifold mounted rectangular fuel filter, referred to as the Stanadyne 80 IIRC. These do an okay job, but can be quite problematic for some people, from what i've read. I have no experience with them.

93+ will have the FFM (fuel filter manager) and is probably the simplest option for replacement. The filters are easier to get at most all parts stores and is a much better all-in-one unit than the S80.

I'm running a Hughes Fuel Miser torque converter in my K5 (haven't been tested yet), so I can't tell you how it will work. Other than that, i've always run stock TC's. I never messed with transmissions too much.

I do know that the stall speed is one factor at play, but I believe the OEM diesel converters were built stronger to handle the torque and harmonics of the engine. A gas replacement with a good stall speed shouldn't be that much of a weakpoint though. I just remember reading something about them being built stronger.

TC-W3 doesn't smoke at all, in my experience. I never had a single smoking problem with my truck, except for when I had 2 or 3 bad injectors. I never did mess with adding more fuel until I put this new pump on it. Now it smokes LOL

The 82 blocks only downfall is the coarse thread injectors. Otherwise they have bigger valves and better block/head metallurgy (more nickel=strength).

The injectors are all pretty much the same except for their body. If that ebay store doesn't have coarse thread, Mylex Int. on Ebay should have them, they were nice people to personally deal with as well. I had to order some internal pump parts and seals from them last summer and they were happy to help an Eskimo LOL

As for the TC, I'd ask your converter builder, He should be able to answer those questions a little better for you. None of the TC's I could find, with a 1200 stall were all quite expensive. You might be able to get away with a 1400-1500 stall as well, which I believe was stock.

If your truck has the factory duals, they should be 2.25" which is an entirely adequate size. People say good things about 2.5" though, I discovered part of my exhaust is 2.5"...so I only need to get some U, J and some angle bends and finish it up and add some chambered/welded mufflers on there too.

I love how these motors sound and they can certainly pull well too. I haven't done any long distance towing with my 6.2L but it works incredibly well as a recovery vehicle, pulling people out of ditches and snowbanks and stuff. I stick it in 4HI or LO (depends on road conditions) and I can basically idle out most stuck vehicles. I can't say the same for my 6.0L 2500HD Silverado...which spins it's wheels when you push the engine hard.

Pull the oil pan, check the main bearing webbing for cracks.

Otherwise, you can pull the bearings and inspect them, definitely replace the harmonic balancer (any good replacement) and check out the flexplate...replace if necessary (They are only cheap). Only thing I would add is to get a J-Code intake manifold and get rid of the EGR altogether. The manifolds are just a huge burden to your diesel. A diesel is always trying to take in as much air as it can get and they like it if they can get more. The difference between C-Code (EGR) to J-Code (No-EGR) is like night and day. It feels like a whole new beast once it's not restricted anymore.

Plugging the EGR is a step in the right direction, but the manifold with no EGR getting in the way of the intake ports is the best manifold. All said, just capping off the EGR and pulling the solenoids out was enough to feel like a 10HP difference in the butt dyno. It was actually able to climb over 60MPH and that was amazing. It is even better now ;D

Diesels love to breathe and take in as much air as possible at all times, so giving them a nice big single plane J-code manifold will make your engine very happy.

Even without adding extra fuel to get more performance, you will notice that the engine just reacts to all situations with more aggressiveness. This will keep your engine cooler and increase volumetric efficiency, all while not having to work as hard. It's a win-win.

Hydroboost is a hydraulic alternative to vacuum boosted brakes. The hydroboost unit takes the place of the big ugly vacuum booster and only requires extra lines to run from the PS pump and to the steering box. Just grab yourself a spare, reseal it and swap it in. You should be able to buy or have new PS lines made up around your area somewhere. I get all mine made at a local semi-shop, they even do the press on fittings.

Worry more about getting the 6.2 breathing well, the injector are popping right (pull em out and take em to a diesel shop), the IP is advanced a few hairs and the glowplugs heating up. I recommend Bosch Duratherms or ACDelco 60G glow plugs, plus a manual glow plug controller setup. There are a few DIY's online to do it, even without the factory solenoid. I'll send you some links if you are interested. I love having control over my glow time. It means I can get reliable starting even up here in the arctic.

BTW, I had this saved for a while, because it's the best price for some quality starters:

http://www.db-starter-alternator.com...rque-6469.aspx

Also!

Get yourself a starter brace/bracket, if one isn't already on your engine. It's a small little stamped steel bracket but it will save the life of your starter and your block.

I know because the PO of the truck didn't put one back on and broke off a chunk of the block. Luckily there was enough thread left to get a helicoil in and it's been holding since the early 90's...according to him.

Most will say a cracked motor is an automatic death sentence, but one guy in a thread claimed that his block had a crack running in one web. He could feel it catch his finger when he ran it across, which is not good. But he installed DSG stud girdle and ARP stud kit, then claimed that the girdle pulled the crack back together and it's held ever since. So even if you find a minor one, you're only a few parts away from correcting the problem.

The wiring looks like a lot, but it's quite simple once it's all laid out. I've got to try and draw a diagram for you, in terms of the essential wiring, as I can remember it :P

Most of the relays and sensors can be eliminated. If it's got an EGR and EPR valve (should be mounted to the pass.side of the intake manifold) you can just toss them to the side and forget about em. The glow plug system can be vastly simplified if you were going to go full manual control. I recommend upgrading to 1/0 battery cables because the whole electrical system will love you LOL

I'll see what I can cook up on MSPaint before I start drinking too much and explain it a little better. The best thing to do in the mean time, is to lay out the harness as best as you can, then start looking through it for worn out, cracked or damaged wiring and fix/optimize while it's easy to get too. That includes replacing the fusible links coming off of the starter and heading up the back of the engine, into the main harness.

These engines might become something you love or loathe...I hope I didn't steer you down a bad path, but I've convinced a few people to give them an honest try and they have all been quite pleased with these "little" diesels.

Otherwise, the engine is controlled mechanically by the injection pump. It controls idle, fuel volume and pressure, timing, injection and a few other minor things. It sounds like a giant expensive, weak waste of time, but they are quite marvelous little mechanical pieces, yet sooooo simple. It's weakness comes from the fact that the pump is lubricated and cooled by the fuel passing through it, not from engine oil like the Cummins and most other diesels (6.9/7.3L IDI Ford diesels use a reverse spinning version of our pumps too). This makes it too dependant on fuel lubricity and quality.

It's just a matter of supplying the pump with more than enough fuel volume and adequate pressure, so it never runs low and potentially hot. It's also important to add something for lubricity. I mentioned using TC-W3 low smoke formula and I could hear a difference between straight diesel and diesel with the additive. The engine sounded a lot less "mechanical" when it was just rotating. It ran a little smoother and was slightly quieter in all ranges.

I think that's why I was able to keep my pump for that long, but it was the OEM pump (with at least one reseal and some minor upgraded internal parts). It's just a matter of a worn out head and rotor on the pump and needs to be replaced. You can buy the parts individually or just buy another pump that is resealed, calibrated and tested. I've seen brand new rotors on Ebay for under $300 which, when calibrated, will run waay more reliable than any remanufactured unit, but it's the same for all parts...

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